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ar15 buffer question

Discussion in 'Rifle Country' started by greyling22, Apr 28, 2012.

  1. greyling22

    greyling22 Well-Known Member

    My ar is transforming. I'm swapping a midlength upper (lower had a carbine buffer tube) out for a RRA 20" predator upper (if it will ever ship). I have the regular carbine buffer and an h2 buffer. I'm trying to find out if the new upper will run on my existing lower/buffer combination.

    My google-fu gives me an answer of "it might work fine, you'll have to try and see" can anybody give a firm answer?
  2. Zerodefect

    Zerodefect Well-Known Member

    It'll work fine. But working fine deosn't mean it's correct. It's allways a good idea to do some tuning with buffer weights. You can get a H3 buffer and remove weights as needed.

    I'll let the others chime in on exactly what they use, I just experiment.

    Anyone have any recommendations for any carbine buffers for 18" rifle gas uppers as well?
  3. matrem

    matrem Well-Known Member

    I've ran 20" uppers on rifle buffers through H2 buffers with no problems.
    Havn't tried one with H3.(guessing it would work though)
    As mentioned , "tuning" the buffer weight to your rifle just makes the recoil easier to deal with.
  4. TonyAngel

    TonyAngel Well-Known Member

    Just watch the ejection pattern. If it's throwing the brass forward (say a 2:00 position or farther forward) try a heavier buffer. If it's throwing the brass behind you (5:00 position or more) try a lighter buffer. You want about a 3 to 4:00 ejection.
  5. greyling22

    greyling22 Well-Known Member

    well that is really helpful tony. thanks.
  6. madcratebuilder

    madcratebuilder Well-Known Member

    As you can see from this buffer weight chart the 20" rifle upper is designed to operate with a 5.6oz buffer.

    Rifle 5.2 oz
    Carbine 3.0 oz
    H buffer 3.8 oz
    H2 buffer 4.6 oz
    H3 buffer 5.6 oz
    ST-T2= 4.3oz.
    ST-T3= 5.4oz

    I have rifle uppers run fine with H and H2 buffers.

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